#include <sys/types.h>
#include <libavformat/avformat.h>

int main(int argc, char const *argv[])
{
    u_int8_t *buf1 = av_mallocz(10);

    u_int8_t *buf2 = av_mallocz(3);

    buf2[0] = 100;
    buf2[1] = 101;

    memcpy(buf1 + 2, buf2, 3);

    for (size_t i = 0; i < 10; i++)
    {
        printf("%d ", buf1[i]);
    }
    printf("\n");

    return 0;
}
